Chemicals that reach the soil may potentially have harmful effects on
the non-target invertebrate fauna present, including organisms that
are important in the processes that result in the breakdown of organic
litter. There is, therefore, a requirement to demonstrate that such
chemicals have no lasting effect on the degradation rate of organic
matter lying in treated soil. Although there is currently no internationally-agreed
guideline, evaluation techniques currently being considered in Europe
involve so-called ‘litterbag’ studies. For these, parcels
of organic straw are buried in soil at the time of treatment and assessments
are made at regular intervals of their rate of decomposition. We have
experience with such litterbag studies and can offer advice on their
design and implementation.

We are also able to carry out field studies to determine the effects
of treatments on the soil meso- and macro-fauna. Standard ecological
sampling methods and extraction techniques (such as Tullgren funnels)
are used in making a full faunal audit of soil invertebrates both before
and at intervals after treatment. This is one of the best ways for assessing
gross effects on key groups such as springtails (Collembola) and soil
mites.